This relates to integrated circuits such as integrated circuits with mask-programmed layers.
Programmable logic devices are well known. Programmable logic devices can be programmed by a user to implement a desired custom logic function. In a typical scenario, a logic designer uses computer-aided design (CAD) tools to design a custom logic circuit. When the design process is complete, the tools generate configuration data. The configuration data is loaded into programmable logic device memory elements to configure the devices to perform the functions of the custom logic circuit. In particular, the configuration data configures programmable interconnects, programmable routing circuits, and programmable logic circuits in the programmable logic devices.
Structured application-specific integrated circuits (sometimes referred to as structured ASICs or mask-programmed integrated circuits) are another well known type of integrated circuit. Structured ASICs can exhibit reduced unit cost and power consumption compared to electrically programmable integrated circuit. Unlike electrically-programmable logic devices, once a structured ASIC is manufactured, the structured ASIC is locked into a particular custom logic design and cannot be reconfigured to implement another custom logic design. Structured ASICs are manufactured using standard logic layers and custom routing and interconnect mask layers. The standard logic layers are common to all potential custom logic designs that the structured ASICs are capable of implementing. However, unique custom routing and interconnect layers are required for each custom logic design.
Because of the differences between programmable logic devices and structured ASICs, a given user design may not have the same operating characteristics when implemented using structured ASICs as that design has when implemented using programmable logic devices. It would therefore be desirable to provide devices that can implement a given user design with operating characteristics that are similar to, or exactly the same as, when that user design is implemented in a programmable logic device.